Carbureter.



, G. M. BROWN CARBURETER. APPL'iCATION FILED pcta, 1913.

Patented Aug. 24,1915.

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CARBURETER.

Application filed October 3, 1913.

State of Massachusetts, have invented new and useful Improvements in Carbureters, of which the following is a specification.

This invention relates to carburetors, and its object is to provide a simple and eflicient carbureter for use in conjunction with internal combustion engines.

My improved carbureter is so constructed that when once properly adjusted it requires no regulation of the liquid fuel or of the air entering the mixing chamber, and that a thorough and complete mixing ofthe fuel and air, and an even and powerful quality of explosive mixture, will be produced, without waste of the fuel, irrespective of the speed of the engine.

The invention consists in a group of functionally related factors of which the cooperative performance insures a practically perfect gaseous mixture of air and vaporized' volatile fuel and automatically regulates the proportion of air and fuel to suit varying conditions imposed by the engine which is supplied by the carburetor, and by external conditions of temperature and humidity of the surrounding air.

The cardinal factor which characterizes my invention in its more generic aspect is a centrifugal separator, which cooperates functionally with 'the air supply, volatile liquid fuel supply, and air-and-fuel mixture duct. The primary function which the centrifugal separator performs in this environment is the separation from the gaseous content of the carburetor of that portion of volatile fuel which persists in liquid form,

so that only completely volatilized fuel is I allowed to pass to the engine in mixture with air. important, function, performed by the-centrifugal separator in what I conceive to be the best example of my invention, is supplying compensatory fuel vapor by evaporation of liquid volatile fuel from the surfaces of the separator, an evaporation which automatically maintains. a proper fuel-proportion in the combustible mixture supplied to the engine, and automatically adjusts the inspirative draft upon the liquid fuel supply duct, A secondary factor, contributing to the characteristics of my invention in its more specific aspects, is an in-draft air regu- Specification of Letters Patent.

A secondary, but none the less quite Patented A11 24, 1915.

Serial No. 793,250.

lator which, operating in conjunction with the usual throttle valve in the mixture duct leading to the engine, adjusts the pressure in the mixing chamber of the carbureter to variations in degree of throttle opening, thus graduating the pressure under which the centrifugal separator operates.

In the accompanying drawing which illustrates in vertical section a carbureter embodying the invention in one form, A represents a mixing chamber, of metal, glass or other suitable material, which is preferably substantially spherical in form, and may be made in two sections screwed together as shown.

A fuel nozzle B, made with a restricted delivery passage enters through the bottom.

of the mixing chamber A, and is screwed or otherwise secured in place in the wall of the chamber. Opposite the nozzle B is a deflector plate 6, or other suitable form of atomizing device to break up into small particles or form into spray, the jet of fuel issuing through nozzle B. It will be understood that the fuel may be gasolene, kerosene, other or other volatile fluid, for which the engine to be supplied by the carburetor is adapted. The atomizing device I) may be supported in the mixing chamber by legs I). In order to regulate the flow of the fluid and the influence of the suction to which it is subjected the nozzle B is made adjustable in the wall of the chamber A, so that it may be projected a greater or less 'distance into the chamber. The lifting force of the vacuum within the chamber will be found stronger near the center of the chamber than near the periphery. Thus the velocity of the fluid and consequently the consumption of the fuel and its relation to the demands of the engine and the volume of the air; may be varied.

C represents an air inlet tube or pipe, en-

tering the mixing chamber A through the top, and curved or bent as shown, so that its mouth will face away from the center of the mixing chamber and toward the wall.

. D is an outlet pipe for the explosive mixture leading to the engine, and also enters through the top of the'mixingchamber, and is similarly curved or bent, but in the opposite direction, so-tha't its mouth will face away from the center If the chamber toward the wall opposite to that faced by the mouth of pipe C. It w ll be understood that the pipes C and '1) need not necessarily enter the has a shutter F, partially closing the pipe and operated in unison with the throttle valve E by means of the link connection Gr, so that when the throttle E is opened or closed more or less, the shutter F will also open or close more or less.

The fuel nozzle B communicates with the vessel H, which may be supplied with the gasolene or other fuel from a tank in the usual manner, through pipe h, and is secured directly to the under side of the mixing chamber A. The pipe in in supplying the vessel H is controlled by a ball valve h connected to a float J, herein shown as annular in form and surrounding the nozzle B. As the fluid fuel is withdrawn from vessel H through nozzle I3, the float J will fall, open the valve h and admit more fuel through The valves E and F being opened, more or less according to controlling external conditions, and the engine supplied by the carbureter being in operation, a strong in-draft is set up in the carbureter. Air entering at the duct C- impinges obliquely against the curved inner wall of the chamber A and.

whirls centrifi'lgally, passing by the nozzle of the volatile fuel duct B and inspirating volatile fuel, which is atomized or sprayed as it issues from the duct B. The centrifugal motion of the current of air throws the particles of fuel which persist in liquid form outwardly against the walls'of thechamber A; larger particles of liquid are thrown to the circumference of the rotating stream more readily than smaller particles, so that the liquid globules, which by reason of their size are best qualified to delay complete evaporation, are with the greatest certainty deposited on the inner surface of the chamber A,there to spread as a thin film in close adhesive contact, with the solid material of which the chamber A is composed. lVhile all of the air and vaporized fuel passes eventually into the mixture duct D, a considerable proportion of the mixture at any given moment in the chamber A whirls repeatedly around,

making the centrifugal vortex complete. The

be drawn from the float-chamber if the latchamber A thus performs the function of an air and fuel mixing chamber and also that of, a centrifugal separator. The gas-pressure in this separator chamber is least at the center and greatest near the circumference, by reason of the centrifugal action. Therefore, if the nozzle of the liquid fuel duct B is adji'lsted to a position near the center of the centrifugal vortex, the vacuum-draft on the liquid will be by so much increased. This will, of course, be offset by the increased vertical distance through which the fuel has to ter remains at the same position. I prefer, however, to locate the nozzle of the fuel inlet duct B at a point in'the whirling body of air near to the surface of the chamber A,.so that liquid fuel, as distinguished from-vaporized fuel, may be the more readily deposited on the surface of the chamber A. Moreover, in order that liquid spray may not penetrate too far into the chamber A, I provide the baflie plate 6, which assists also in breaking up the liquid spray and furnishes some evaporating surface in supplement to the walls of the chamber A.

Besides mechanically removing liquid particles from the air stream by depositing them through centrifugal separative action on the walls of the chamber A, the separator-mixer performs the function of supplying a continuously replenished film of volatile liquid to the walls of the chamber, and this film continually evaporates, enriching the combustible mixture with truly gaseous fuel. Thus the carbureter acts as a combined spray and surface carbureter, contributing the values of each type, without involving the characteristic defects of either.

The vacuum draft on the liquid supply duct is automatically qualified and regulated by the evaporation of liquid fuel deposited on the chamber walls. demand for combustible mixture is made on the carbureter, the film of liquid fuel on the chamber walls responds by, more rapid evaporation due to lowered pressure and increased velocity of flow of air in the chamber, checking what otherwise might be an unduly violent influx of liquid fuel into the chamber, since increased rate of evaporationwill-tend to raise the vapor pressure in the chamber.

lVhen the engine is throttled by partial closure of the valve E, the valve F also increases its constrictive effect on the air duct C. This produces a lowering of pressure in the chamber A, to a degree greater than would be the case if valve F alone operated to vary the effective cross section of the passages, and therefore the lowered pressure in the chamber A compensates for the lower velocity of flow, thus insuring afull delivery of liquid from the duct- B at a time when a richer combustible mixture is likely to he demanded.

Such are the automatic regulating and If a sudden increased compensating faculties of my improved car bu reter that I have found it entirely feasible to dispensewith a needle valve or any other adjuster of theliquid fuel duct, and with a M le -obtained.

rieties of carbureters) which is required in modern internal combustion engine practice,

I believe the most important characteristic of my-lmproved carbureter to be the separation of-per'sistently liquid fuel par- Copies of this patent may be obtained for ticles from the stream which enters the engine. manifold or supply duct. The other characteristics above described, follow as incidents to this main characteristic.

The shape and proportions of the centrifugal separatonchambcr may, of course, be Widely varied, to suit the notions of the designers or the requirements of particular engines-but the characteristic utility of my invention will be served in any carbureter in which the liquid fuel particles which might otherwise be drawn into the engine, are con trifugally" separated from the mixture and deposited upon surfaces from which the liquid may evaporate according to the fluctuating demand.

. The spherical form of gas mixing and liquid separating chamber, shown and described herein, has proved effective in practice, and the sphere is therefore believed to be the preferable form of this characteristic member of my improved carbureter. Plenty of space is afforded on either side of the direct path between the ducts C and D, to allow the gaseous contents of the chamber i to stir about'and mix thoroughly, while the vertical or eddying motion always facilitates the separation from the gases of liquid particles so long as those persist.

The location of the fuel float-chamber immediately below the delivery nozzle Bis important, because the effective level, or head, of the liquid fuel, is not affected by changes in the inclination of the carbureter to the horizontal normal position, changes which take place constantly when a motor is traveling on the road. Since no mechani= cal regulation is necessary or desirable in this improved carbureter, the liquid fuel inlet is not so constricted as in carbureters heretofore in general use, and any change of relative level between the liquid in the float chamber and the delivery opening of the liqiiicl duct B will affect my improved carureter more than a similar change will affeet the behavior of carbureters of the present standard forms.

WVhile' I believe that a substantially spherical form is the best for the mixing chamber, my invention is not restricted to that parti cular form. Good results may be obtained if instead of being spherical, the lower part of the chamber only is hemispherical, while the upper part might be of other form. Indeed manv of the advantages of my invention might be realized with a mixing chamber of other than spherical or hemispherical forms, the important characteristics being that the chamber should be large relatively to the passages; and that the flow of the air therethrough should be in tortuous currents and eddies.

It will be observed that with this invention no needle valves, and no springs are required. The'inflow of air, and the speed of the fluid jet are automatically responsive to and regulated by the degree of vacuum, or tension produced. by the engine and controlled by the throttle E.

'I claim: v

1. In a carbureter, the combination of a spherical mixing chamber, a liquid fuel duct. entering said chamber at one side, and and;

air inlet duct and a mixture delivery duct each extending into the spherical chamberand presenting their respective openings to ture duct and the other in the air inlet duct,

the two valves connected to move in unison. Signed by me at Boston. lllassachusetts, this 16th day 0 September, 1913.

GEORGE M. BROWN.

Witnesses Ronna'r CUSHMAN, CHARLES D. lVoonBnnuY.

five cents each, by addressing the Commissioner of Batents,

Washington, D. C. 

